1 Department of Molecular Imaging and Nuclear Medicine, Indraprastha Apollo Hospitals, SaritaVihar, Delhi-Mathura Rd, New Delhi 110076, India.
2 Department of Urology and Andrology, Indraprastha Apollo Hospitals, SaritaVihar, New Delhi, India.
AJR Am J Roentgenol. 2018 Dec;211(6):1246-1253. doi: 10.2214/AJR.18.19585. Epub 2018 Oct 9.
The current study was designed to test the diagnostic performance of Ga-prostate-specific membrane antigen (PSMA) PET and multiparametric MRI along with clinical parameters in the characterization of prostatic lesions.
Eighty-two men with 63 malignant and 21 benign histologically proven prostate lesions who underwent complete clinical workup were included in this retrospective study. All patients underwent simultaneous whole-body Ga-PSMA PET/MRI with dedicated multiparametric MRI. Prostate Imaging-Reporting and Data System (PI-RADS) version 2 assessment was used for predicting the likelihood of cancer. Uptake of Ga-PSMA was recorded by adopting the copy-and-paste function of ROIs defined on MR images. ROC and combined ROC analyses were performed to test the diagnostic accuracy of individual and combined parameters. Spearman analysis was used to assess the correlations.
PSMA uptake (maximum standardized uptake value) was significantly different among tumors with Gleason scores of 7, 8, and 9, with the lowest uptake in tumors with a score of 7 and the highest uptake in tumors with a score of 9. There was a significant difference between early- and delayed-phase PSMA uptake in malignant prostatic lesions (p < 0.01). Significant correlations were observed between delayed and differential PSMA uptake and PI-RADS category (p < 0.01 and < 0.01, respectively), digital rectal examination findings (p = 0.01 and < 0.01, respectively), Gleason score (p = 0.05 and < 0.05, respectively), and prostate-specific antigen levels (p = 0.01 for both). Combined ROC analysis of prostate-specific antigen levels, digital rectal examination findings, multiparametric MRI, and differential PSMA uptake were able to characterize prostatic lesions with a mean (± SD) AUC of 0.94 ± 0.03, compared with their individual AUCs of 0.77, 0.70, 0.82, and 0.88.
Gallium-68-PSMA PET combined with multiparametric MRI showed high diagnostic accuracy for prostate cancer diagnosis compared with either multiparametric MRI or PET alone or with clinical factors (e.g., digital rectal examination or prostate-specific antigen level) alone, and the combination further improves characterization of prostatic lesions.
本研究旨在测试 Ga-前列腺特异性膜抗原（PSMA）PET 和多参数 MRI 联合临床参数在前列腺病变特征描述中的诊断性能。
本回顾性研究共纳入 82 名经组织学证实患有 63 例恶性和 21 例良性前列腺病变的男性患者。所有患者均行全身 Ga-PSMA PET/MRI 检查，同时行专用多参数 MRI 检查。采用前列腺影像报告和数据系统（PI-RADS）版本 2 评估预测癌症的可能性。通过复制和粘贴在 MR 图像上定义的 ROI 的功能记录 Ga-PSMA 的摄取。进行 ROC 和联合 ROC 分析以测试个体和联合参数的诊断准确性。采用 Spearman 分析评估相关性。
PSMA 摄取（最大标准化摄取值）在 Gleason 评分 7、8 和 9 的肿瘤之间存在显著差异，评分 7 的肿瘤摄取最低，评分 9 的肿瘤摄取最高。恶性前列腺病变的早期和延迟期 PSMA 摄取之间存在显著差异（p < 0.01）。延迟和差异 PSMA 摄取与 PI-RADS 类别之间存在显著相关性（p < 0.01 和 < 0.01），与直肠指诊结果（p = 0.01 和 < 0.01）、Gleason 评分（p = 0.05 和 < 0.05）和前列腺特异性抗原水平（p = 0.01）相关。前列腺特异性抗原水平、直肠指诊、多参数 MRI 和差异 PSMA 摄取的联合 ROC 分析能够以 0.94 ± 0.03 的平均（± SD） AUC 对前列腺病变进行特征描述，而其各自的 AUC 为 0.77、0.70、0.82 和 0.88。
与多参数 MRI 或 PET 单独或与临床因素（如直肠指诊或前列腺特异性抗原水平）单独相比，Ga-68-PSMA PET 联合多参数 MRI 对前列腺癌诊断具有较高的诊断准确性，且联合分析可进一步提高前列腺病变的特征描述能力。
